How Long Do Onions Last?

Bought a big bag of onions on a sale and not sure if they will last long enough for you to use all of them? No worries, with this short guide you’ll know how long various types of onions last, and how to store them, so they keep quality for as long as possible. We’ll talk about freezing onions, too.

And what if you’ve already cut the onions? We cover that as well.

Read on to learn all about the shelf life, storage practices, and spoilage of onions.

Onions

Photo by Lars Blankers.

How Long Do Whole Onions Last? How To Store Them?

Before we get into the nitty-gritty, we need to touch upon the various kinds of onions available on the market. And there are a lot of varieties of onions you can buy: white, yellow, sweet, red, and even pearl.

For the sake of this article, all you need to know is that sweet onions don’t last as long as other types (often called storage onions). One of the reasons behind that is that they have more water than other varieties. In short, if you store all kinds of onions, and aren’t sure which ones to start with, go with sweet onions.

When it comes to shelf life, it all depends on the storage conditions. The ideal temperature for storing onions is between 45°F (7° C) and 55°F (13°C). So it’s a bit above fridge temperature, and noticeably below room temp. If you have a cellar, basement, or any other place that maintains a similar temperature no matter the weather, you can keep sweet onions in there for a month, maybe a month and a half, and storage onions for 2 to 3 months.

Unfortunately, most of us don’t have access to a storage space with the ideal conditions, so we have to work with what we’ve got. That leaves us with storing these root veggies in either the pantry/kitchen or in the fridge. For sweet onions, the refrigerator is the better choice, and they should last there for up to a month. Storage onions last up to a month at room temperature (or less, if it’s super warm inside, like 77°F (25°C) during the day) and up to two months in the fridge. Peeled whole onions should always be refrigerated (OA).

To make sure your onions last as long as they can, make sure the onions are well ventilated. That means no plastic bags (OA). Mesh bags are best for onions because they are breathable, and that’s why you can often find onions and garlic in such bags in the supermarket. For sweet onions, it also helps if you pack each one in a paper towel or newspaper before refrigeration (OA). That helps them keep dry. And keep onions away from ethylene-producing fruits and veggies such as bananas, apples, or tomatoes so that they won’t spoil early.

Sliced red onion

Photo by Burhan Rexhepi.

How Long Do Cut Onions Last? How To Store Cut Onions?

Cut onions last about 7 to 10 days in the fridge. Place halves, rings, or cut pieces in airtight containers and refrigerate them.

When you need to scoop a tablespoon or two of cut onions, always do this with clean cutlery so that you won’t contaminate the rest.

If this period is to short for your needs, consider freezing the leftovers.

Can You Freeze Onions?

Unlike most other veggies, like zucchini or broccoli, whole onions last a long time. So unless you forgot about them after buying, you should be able to use them before they rot. But in some rare cases, you might want to freeze those onions anyway.

For leftover cut onions, the situation is different. They don’t last as long, so if you have no plans of using them in sight, freezing is the way to go.

Before we get into the specifics of freezing onions, you need to know that this process degrades the texture of the onion. And as a result, the veggie isn’t much good for eating raw (OAF). But using them in cooked dishes should be okay. With that in mind, let’s see how the freezing process looks like:

  1. Peel and cut the onion. If you have a whole bulb, it’s time to cut it up. Think about how you’re going to use the veggie and cut accordingly. If you’re not sure, dice it. Diced onions are probably the most versatile to use.
  2. Portion the onion into freezer bags or containers. Put in each bag as much as you need for a single dish. This makes thawing super easy. Alternatively, spread the onions on a cookie sheet and flash freeze them before transferring to the bags. This way, you will be able to scoop some of the onions without thawing the whole bag.
  3. If you find it useful, label the bags or containers with name and date.
  4. Freeze the onions.

That’s it. You can keep those onions in the freezer for at least a couple of months.

When it comes to defrosting, the fridge is the way to go. If time comes at a premium, submerge the bag (or transfer the onion into a bag first if it’s in a container) in cold water. A third option is to throw the onions in frozen. If it’s a soup or anything else done on the stove, that’s the easiest option and works well.

Red onion on a brown cutting board

Photo by Webvilla.

How To Tell If an Onion is Bad?

If the onion is moldy or rotten, throw out the bulb. Unless, of course, only a small part of the onion is bad, in which case you can chop it off. Mushy, soft or spongy, or completely dried onions are also done for, and you should discard them.

When it comes to onions that have sprouted, they are perfectly edible, just like sprouted potatoes. Cut off the shoots, then cut the onion in half and remove any remains of the shoots. The onion is now ready for you to use.

As you know, onions have a layer or two of loose skin that you discard while peeling. Sometimes you can find such a brown layer in the middle of the onion, under a few layers of “edible” onion. If that’s the same, you can remove that brown part, and eat the rest. I’ve seen it and done so a dozen times, and never had any issues with it.

Takeaways

  • Sweet onions don’t last as long as storage onions (red, white, yellow, pearl).
  • Store sweet onions in the fridge, where they keep for about a month. You can store storage onions in the fridge for about two months, or in the pantry or kitchen for maybe a month.
  • Cut onions need to be sealed tightly and refrigerated. They last about a week, up to 10 days.
  • You can freeze onions, but frozen and thawed ones work well only in cooking.
  • Sprouted onions are okay to eat, just cut off the shoots outside and inside the bulb.

References

Published July 29, 2019

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